Spark-plug.



L. A. WITTER.

SPARK PLUG.

APPLICATION FILED NOV. 1. I9l6.

$21,94U Patented Apr. 10, 1917.

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Leon nLonfzo W-I'ITER, or JACKSON, MICHIGAN, ASSIGNOB, or ONE-nan}? T0 GusrAvE A. WEBER, or JACKSON. MICHIGAN;

SPARK-PLUG;

' Specification of Letters Patent. I Patented Apr. 10,1917.

Application filed November 1, 1916. Serial No. 128,997.

To all whom itmag concern. Beit known that Lno'ri ALoNzo WITTER a citlzen of the Unlted States, residing at 7 Jackson, county of Jackson, State of Michigan, have invented a certain new and useful Improvement .in Spark-Plugs, and de-- spark plug partly-broken away at the lower end showing'the apparatus embodying my invention secured thereto.

Fig. 2 .is an inverted plan view of the same.

Fig. 3 a detail plan viewof the shutter removed from its mounting.

a is the spark plug having the screwthreaded portion 6 in the usual and .con- Ventional form. 0 indicates the hollow in the lower portion of-thespark plug, and d is the central rod constituting one of the position and extends in the part 7 which is parallel to the plane of the lower end of the plug and closely adjacent thereto.

Upon this portion 7 I pivot a shutter 72 which is provided with an eye vi which engages over the portion 7.

The rod (if is again turned at right angles and extends in the portion 9 below the shutter it so as to support the same in a position at which it is slightly away from the lower edge of the spark plug. There is'a circular aperture j formed through the center of the shutter h, and the walls of said aperture surround the electrode, at a proper sparking distance from said electrode.

The shutter 71. is adapted to close against the-lower end ofthe plug a and to separate the hollow c of said plug from the exploslon chamber of the engine except for the very small aperture j.

I .The operation of the above described device is as follows:

The shutter h is in electrical connection with the spark plug and therefore the spark passes between the electrode cl .and the wall of the aperture 7.

The shutter 72) will be kept in continual motion by the action of the gases in the operation of the engine.

When. compression takes place, or the explosion occurs, or the pressure in the cylinder increases in any way, the gases w ll seek to pass into the hollow 0 of the plug and in so doing will cause the shutter h to close against the end of the plug. When the pressure in the cylinder lowers the gases will expand from the hollow c and assist gravity in carrying the shutter to the lower extremity of its travel where it is held by the portion g of the wire 6 f g.

- Thus should any foreign matter, such as water'or soot, accumulate between the wall of the aperture j and the electrode (Z, the motion of the shutter it will throw it off and it will not form a bridge between the electrode and interrupt the igniting spark.

Vhat I claim is: t

The combination with a spark plug provided with a hollow, an electrode concentric with said hollow, a movable electrode adapted to open and close said hollow and to be actuated by the gases in the cylinder, said second electrode being provided with an aperture surrounding said first electrode and having its walls within sparking distance of the same. 4

In testimony whereof, I sign this specification.

LEON ALONZO WITTEB. 

